Does Acetone Added to Gas Improve Your Gas Mileage? Complete Guide
In this guide: Everything you need to know about adding acetone to gasoline - covering the claims behind acetone fuel additives, what science and testing actually say about gas mileage improvement, the risks and potential damage to your engine, what fuel system components are affected, whether it is safe to use in your vehicle, and answers to the most common questions about acetone as a gasoline additive.
Does Acetone Added to Gas Improve Gas Mileage? Quick Answer
No - there is no reliable scientific evidence that adding acetone to gasoline improves gas mileage. The claim that acetone added to gas improves fuel economy is a persistent online myth that has circulated since the early 2000s, but it is not supported by credible testing, peer-reviewed research, or approval from any automotive manufacturer, fuel standards organization, or government agency. Acetone is a polar solvent that can help non-polar gasoline mix more thoroughly with polar water, and it can clean certain deposits from fuel system components - which is why some users report a marginal, temporary improvement in fuel economy after using acetone. However, this effect is due to fuel system cleaning, not the acetone itself, and acetone poses real risks to rubber seals, plastic fuel lines, elastomer components, and certain metal alloys used in modern fuel systems. At concentrations above 1–2% by volume in gasoline, acetone can corrode rubber fuel lines, degrade塑料components, and damage aluminum fuel system parts. The bottom line: do not add acetone to your gas tank as a fuel economy hack. If your vehicle has fuel system deposits, use a professionally formulated fuel system cleaner from a reputable brand instead.
Bottom line: Acetone does not reliably improve gas mileage. Any perceived improvement comes from fuel system cleaning, not acetone itself - and the cleaning benefit is available from safer, purpose-built fuel additives. Acetone can damage fuel system components at concentrations above 1–2%.
What Is Acetone and Why Is It Added to Gasoline?
Understanding Acetone as a Fuel Additive
Acetone (C₃H₆O) is a colorless, volatile organic compound commonly used as a solvent in nail polish remover, paint thinner, and industrial cleaning products. In the context of gasoline, the claim for using acetone as a fuel additive is based on two main arguments made by proponents: (1) Acetone improves fuel atomization - meaning it helps gasoline break into smaller, more uniform droplets during injection or carburetion, leading to more complete combustion and better fuel economy. (2) Acetone acts as a drying agent that helps separate water from gasoline and burns it more cleanly, reducing the negative effects of water contamination in fuel. Neither of these claims is supported by credible, reproducible scientific evidence. The argument about fuel atomization has been studied in aviation fuel contexts, where acetone is occasionally used as a fuel system ice inhibitor in specific conditions, but this does not translate to measurable fuel economy benefits in automobile engines running on modern gasoline.
| Acetone Property | Detail | Relevance to Fuel |
|---|---|---|
| Chemical formula | C₃H₆O (propanone) | Ketone solvent |
| Polar nature | Moderately polar solvent | Can mix with water and gasoline simultaneously |
| Volatility | High evaporation rate | Burns readily when vaporized |
| Solvent strength | Strong solvent | Dissolves certain fuel deposits |
| Common uses | Nail polish remover, paint thinner, solvent | Not approved as fuel additive |
| Used in aviation fuel | 偶尔 as de-icing agent | Limited, specific conditions only |
| Approved as fuel additive | ❌ No | Not listed by EPA or any fuel standards body |
The Claim: How Acetone Is Supposed to Improve Gas Mileage
The Theory Behind Acetone Fuel Additives
The core claim made by acetone fuel additive proponents is that adding a small amount of acetone to gasoline results in measurable gas mileage improvement. The specific claimed improvement varies widely by source - ranging from 3% to 30% - but most proponents settle on 5–15% as a typical improvement. Here are the main arguments made:
Argument 1 - Improved fuel atomization: Proponents claim that acetone reduces the surface tension of gasoline, allowing it to break into smaller droplets during injection or carburetion. Smaller droplets evaporate more quickly and mix more uniformly with air, creating a more complete burn. The argument is that the fuel burns more efficiently, extracting more energy per gallon and thereby improving fuel economy.
Argument 2 - Water separation and removal: Proponents claim that acetone acts as a drying agent that binds to water molecules in gasoline and carries them through the combustion process more cleanly. Water contamination in gasoline - which can enter through condensation in partially filled tanks, ethanol blend issues, or poor storage conditions - can cause phase separation in ethanol-blended fuels (E10 and higher) and reduce combustion efficiency. The argument is that acetone solves this problem.
Argument 3 - Fuel system cleaning: Proponents claim that acetone dissolves varnish, gum, and carbon deposits from fuel injectors, intake valves, and combustion chambers, restoring performance and improving fuel economy. This argument is the most credible of the three - acetone is indeed a strong solvent and can dissolve certain types of fuel system deposits. However, the same cleaning benefit is available from purpose-built, professionally formulated fuel system cleaners that are specifically designed and tested for use in automotive fuel systems.
What Does the Evidence Actually Say?
Scientific Testing and Real-World Evidence
The scientific evidence for acetone improving gasoline fuel economy is essentially nonexistent. No peer-reviewed study has demonstrated a reliable, reproducible gas mileage improvement from adding acetone to gasoline in automobile engines. Here is what testing has found:
EPA and fuel standards organizations: Acetone is not listed as an approved fuel additive by the Environmental Protection Agency (EPA) under the Clean Air Act, by ASTM International (which sets fuel standards), or by any major automotive manufacturer. None of the organizations that regulate fuel quality or certify fuel additives recognize acetone as an effective fuel economy improver.
Automotive testing: Independent automotive publications and enthusiasts have conducted informal tests adding acetone to gasoline in various concentrations. Results have been inconsistent - some tests report marginal improvements (1–3%), while others report no measurable improvement or even decreased performance. No test has demonstrated the 5–15% improvement claimed by proponents.
The "study" cited by proponents: The most commonly cited evidence for acetone improving fuel economy is a widely circulated document attributed to the U.S. Department of Energy's Oak Ridge National Laboratory from the early 2000s, which reportedly studied acetone as a fuel additive. However, this document has never been authenticated, has not been published in any peer-reviewed journal, and is not available from any official DOE source. It is almost certainly a fabrication or a misattributed document that has spread through internet forums and social media.
The aviation fuel context: Acetone is occasionally used as a fuel system icing inhibitor (FSII) in aviation gasoline (avgas) for piston-engine aircraft, where it helps prevent ice formation in fuel lines at altitude. This is a completely different application with different fuels, different engines, and different operating conditions - it does not translate to automobile gasoline engines.
| Evidence Source | Finding on Acetone + Gas Mileage | Credibility |
|---|---|---|
| Peer-reviewed scientific studies | None demonstrating reliable improvement | High |
| EPA approval / listing | Not listed as approved fuel additive | High |
| ASTM International fuel standards | Not approved as fuel additive | High |
| Major automotive manufacturer endorsement | None | High |
| Independent automotive testing | Inconsistent results; no reliable improvement | Moderate |
| Online forums and testimonials | Mixed; anecdotal at best | Low |
| "Oak Ridge National Lab" study (widely cited) | Not authenticated; likely fabricated | Very low |
The Risks: Why Adding Acetone to Gasoline Is Dangerous
Potential Damage to Your Fuel System
Adding acetone to gasoline carries genuine risks to your vehicle's fuel system and engine components. These risks are well-documented and are the primary reason no reputable automotive organization endorses the practice:
Risk 1 - Rubber and elastomer degradation
Acetone is a strong solvent that attacks rubber, elastomer, and塑料components found throughout modern fuel systems. Modern vehicles use nitrile rubber (NBR), fluoroelastomer (Viton), and various engineered plastics for fuel lines, O-rings, seals, fuel pump components, and fuel injector seals. Acetone can cause these materials to swell, harden, crack, or degrade over time, leading to fuel leaks, reduced injector performance, and premature failure of fuel system components. The risk increases with acetone concentration and exposure time. Fuel system repairs can cost $500–$3,000+ depending on the severity and location of the damage.
Risk 2 - Aluminum and metal corrosion
Acetone can accelerate corrosion in certain aluminum alloys and metal components used in fuel systems, particularly in the presence of water (which acetone can draw into the fuel). While brief exposure to low concentrations may not cause immediate visible damage, repeated or prolonged exposure can lead to pitting corrosion in aluminum fuel system components, including fuel rails, certain fuel pump housings, and fuel pressure regulators.
Risk 3 - Fuel system plastic degradation
Many modern fuel system components are made from engineered plastics (such as polyamide, polycarbonate, and polysulfone) that are chosen for their chemical resistance to gasoline. However, acetone is not in the standard fuel compatibility charts for most of these materials, and damage from acetone exposure may not be immediately visible. Plastic components that appear intact after one treatment may have been weakened at a microscopic level, leading to premature failure over time.
Risk 4 - Unpredictable fuel formulation interactions
Modern gasoline is a complex mixture of dozens of chemical compounds, including ethanol (typically 10% in E10 gasoline), detergent additives, corrosion inhibitors, and anti-oxidation agents. Adding acetone to this mixture can have unpredictable effects on fuel stability, combustion characteristics, and emissions. Acetone may interact with ethanol in ways that increase the volatility of the fuel, potentially causing vapor lock in hot weather or affecting cold-start performance.
Risk 5 - Voiding your warranty
Using unapproved fuel additives - including acetone - in your vehicle can void or partially void warranties on fuel system components. If a fuel system component fails and the manufacturer can demonstrate that an unapproved additive contributed to the failure, they may deny warranty coverage for the repair. Fuel system warranty claims can total $500–$3,000 or more.
Acetone Concentration: How Much Is Too Much?
Safe vs. Dangerous Concentrations
The concentration of acetone in gasoline is the critical variable that determines whether the practice is merely ineffective (low concentration) or actively dangerous (higher concentration). Here is what is known:
| Acetone Concentration | Effect | Risk Level |
|---|---|---|
| <0.5% by volume | Negligible fuel economy effect; minimal material risk | Very low risk (but still not recommended) |
| 0.5–1% by volume | Possible minor cleaning effect from solvent action; minimal documented benefit | Low risk but still not endorsed by any authority |
| 1–2% by volume | Diminishing returns on any benefit; material risk begins to increase | Moderate risk; potential damage to seals and plastics |
| 2–5% by volume | Potential damage to rubber seals and elastomers; fuel system component risk | High risk; can cause fuel leaks and component failure |
| >5% by volume | Significant material degradation risk; potential for fuel system damage | Very high risk; actively dangerous |
The most commonly recommended (though still unendorsed) concentration from online proponents is typically 1–2 oz of acetone per 10 gallons of gasoline - approximately 0.1–0.2% by volume. Even at these extremely low concentrations, there is no demonstrated fuel economy benefit, and the material risk, while lower than higher concentrations, is not zero. At the concentrations sometimes recommended by online proponents (1 oz per gallon or higher), the risk to fuel system components is significant.
What Actually Improves Gas Mileage?
Evidence-Based Approaches to Better Fuel Economy
If you are looking to improve your gas mileage, there are many proven, evidence-based approaches that actually work:
| Strategy | Gas Mileage Improvement | How It Works |
|---|---|---|
| Drive more smoothly | 10–40% improvement | Gentle acceleration and braking reduces fuel consumption |
| Maintain proper tire pressure | 3–5% per tire PSI below spec | Underinflated tires increase rolling resistance |
| Use the correct motor oil | 1–3% improvement | Use manufacturer-recommended grade and viscosity |
| Remove excess weight | 1–2% per 100 lbs removed | Less weight = less work = less fuel |
| Reduce aerodynamic drag | 5–15% at highway speeds | Remove roof racks; close windows at high speed |
| Use cruise control on highways | 5–10% improvement | Maintains consistent speed; reduces throttle cycling |
| Combine trips | Variable | Eliminates cold-start fuel waste |
| Keep engine properly tuned | 4–40% improvement | Bad spark plugs, oxygen sensors dramatically reduce efficiency |
| Use recommended fuel | Variable | Using lower-octane fuel than recommended wastes money |
| Professional fuel system cleaning | 2–5% average | Removes deposits from injectors and intake valves |
| A/C usage | 5–25% in city driving | Heavy A/C load is one of the biggest fuel economy drains |
| Reduce idling | 0.5–2% | Idling burns fuel with zero miles driven |
Professional Fuel System Cleaners vs. Acetone
Why Purpose-Built Fuel Additives Are Safer and More Effective
| Factor | Acetone | Professional Fuel System Cleaner |
|---|---|---|
| Purpose-built for fuel systems | ❌ No | ✅ Yes |
| Tested for material compatibility | ❌ No | ✅ Yes |
| EPA-registered or approved | ❌ No | ✅ Many are |
| Manufacturer endorsement | ❌ None | ✅ Some (BG 44K, Chevron Techron, Lucas) |
| Concentration precisely calibrated | ❌ No | ✅ Yes |
| Proven fuel economy improvement | ❌ No | ✅ Marginal (2–5% average) |
| Demonstrated deposit removal | ⚠️ Some | ✅ Yes - tested and proven |
| Risk to seals, plastics, metals | ⚠️ Yes - concentration dependent | ✅ Low - formulated to be safe |
| Warranty implications | ⚠️ May void warranty | ✅ Generally safe under warranty |
| Cost per treatment | Low (industrial solvent price) | $5–$20 per bottle |
| Professional product availability | N/A | ✅ Available at any auto parts store |
Frequently Asked Questions
Q1: Does adding acetone to gas improve gas mileage?
No - there is no reliable scientific evidence that adding acetone to gasoline improves gas mileage. The claim that acetone improves fuel economy is an internet myth that has circulated since the early 2000s, but it is not supported by peer-reviewed research, EPA approval, ASTM fuel standards, or endorsement by any automotive manufacturer. Some users report marginal improvements after using acetone, but these improvements are most likely due to fuel system cleaning (acetone is a strong solvent) rather than any inherent property of acetone that improves combustion efficiency. The same or better cleaning benefit is available from purpose-built fuel system cleaners that are tested, approved, and safe for use in automotive fuel systems. Meanwhile, acetone poses real risks to rubber seals, plastic fuel lines, and metal components in modern fuel systems, especially at concentrations above 1–2%. Do not add acetone to your gas tank as a fuel economy hack.
Q2: How much acetone should I add to my gas tank?
You should not add acetone to your gas tank at any concentration - it is not recommended, endorsed, or approved by any automotive manufacturer, fuel standards organization, or government agency, and it poses real risks to your fuel system. If you are determined to use acetone despite the risks, online proponents who advocate the practice typically recommend 1–2 oz of acetone per 10 gallons of gasoline (approximately 0.1–0.2% by volume). At this concentration, there is no demonstrated fuel economy benefit, the material risk to fuel system components is relatively low, but it is not zero. At higher concentrations - which some online sources recommend - the risk of damage to rubber seals, plastic fuel lines, and aluminum components increases significantly. The honest answer: there is no safe and effective amount of acetone to add to gasoline for fuel economy purposes.
Q3: Is acetone safe for modern fuel injection systems?
No - acetone is not safe for modern fuel injection systems. Modern fuel injection systems use a wide range of rubber, elastomer, and plastic components that were not designed or tested for compatibility with acetone. While brief exposure to very low concentrations (below 0.5%) may not cause immediate visible damage, repeated exposure can degrade rubber seals in fuel injectors, fuel pressure regulators, fuel pump components, and fuel lines. Modern direct-injection engines are particularly sensitive to fuel system cleanliness and fuel formulation - using unapproved additives can damage high-pressure fuel pumps, fuel injectors, and combustion chamber components in ways that are expensive to repair. The repair cost for a damaged fuel injector or fuel pump in a modern vehicle can easily exceed $1,000–$3,000.
Q4: What does the Oak Ridge National Laboratory study say about acetone and fuel economy?
The document attributed to Oak Ridge National Laboratory that is widely circulated online as evidence for acetone improving fuel economy is almost certainly not a genuine ORNL document. It has never been authenticated by Oak Ridge National Laboratory, has not been published in any peer-reviewed scientific journal, and is not available from any official DOE or ORNL source. The document appears to be a fabrication or misattributed document that has spread through internet forums, social media, and word of mouth since the early 2000s. No credible scientific institution, government agency, or automotive manufacturer recognizes this document as a valid source. The fact that this is the only "evidence" cited by acetone fuel additive proponents - and that it cannot be independently verified - is itself strong evidence that the claim is not scientifically credible.
Q5: Can acetone help remove water from gasoline?
Acetone is a moderately polar solvent that can mix with both water and gasoline, which is the theoretical basis for the claim that it helps remove water from fuel. However, this does not mean it is a safe or effective solution for water contamination in gasoline. In modern E10 gasoline (10% ethanol), ethanol already performs the function of water absorption - ethanol binds to water molecules and keeps them in solution, preventing phase separation. Adding acetone to ethanol-blended fuel may actually interfere with this process in unpredictable ways. For non-ethanol gasoline or for situations where significant water contamination has occurred (such as a fuel system that has been compromised), the proper solution is to have the fuel system professionally drained, cleaned, and refilled - not to add a solvent that may cause more damage. Water in fuel can cause corrosion, fuel pump damage, and engine performance problems; treating it with an unapproved additive is not a reliable solution.
Q6: What fuel additives actually improve gas mileage?
The honest answer is that most fuel additives marketed as "fuel economy improvers" do not deliver significant, reliable gas mileage improvements in a properly maintained vehicle. The one exception is professional fuel system cleaners - products specifically formulated to remove deposits from fuel injectors, intake valves, and combustion chambers. In vehicles with significant fuel system deposits (typically vehicles over 30,000 miles without a fuel system cleaning), professional fuel system cleaners can restore 2–5% fuel economy on average. Products like BG 44K, Chevron Techron Complete Fuel System Cleaner, and Lucas Fuel Treatment are widely available, professionally formulated, and have a track record of demonstrated effectiveness without the risks associated with unapproved additives. For genuinely improving gas mileage, the most effective approaches are driving habits (smooth driving, maintaining proper speed, avoiding unnecessary idling), proper vehicle maintenance (tire pressure, engine tune-up, clean air filter), and reducing vehicle weight and aerodynamic drag.
Q7: Does acetone void my car's warranty?
Yes - adding acetone or any unapproved fuel additive to your gas tank can potentially void or partially void warranties on fuel system components. Most automotive warranties exclude damage caused by the use of "non-recommended fuels, fluids, or additives." If a fuel system component fails and the manufacturer can demonstrate that an unapproved additive contributed to the failure, they may deny warranty coverage for the repair. Fuel system warranty repairs - including fuel pump replacement, fuel injector replacement, and fuel line repairs - can cost $500–$3,000 or more out of pocket if warranty coverage is denied. The risk of voiding a warranty is particularly high with acetone because it is not an approved additive, it is known to be potentially damaging to fuel system components, and no automotive manufacturer has endorsed its use.
Q8: Are there any legitimate uses for acetone in fuel?
Yes - acetone has one legitimate use in specific fuel applications: it is occasionally used as a fuel system icing inhibitor (FSII) in aviation gasoline (avgas) for piston-engine aircraft. In this context, a small amount of acetone is added to avgas to prevent ice formation in fuel system components at high altitude, where temperatures can drop well below freezing and moisture in fuel can form ice crystals. This is a well-established practice in aviation, but it is specific to avgas, not automobile gasoline, and the operating conditions (altitude, temperature extremes, specific fuel formulations) are completely different from automotive use. Beyond aviation, acetone is used as a solvent in some industrial and racing fuel applications where it serves as a carrier solvent for specific additive formulations - but these are professionally formulated products, not raw acetone added directly to fuel.
The Bottom Line: Does Acetone Improve Gas Mileage?
No - adding acetone to gasoline does not reliably improve gas mileage. The claim is not supported by peer-reviewed scientific evidence, EPA approval, ASTM fuel standards, or endorsement by any automotive manufacturer. Any perceived improvement from adding acetone to gas comes from fuel system cleaning - acetone is a strong solvent that can dissolve certain deposits from fuel system components - but the same cleaning benefit is available from purpose-built, professionally formulated fuel system cleaners that are specifically tested and approved for use in automotive fuel systems. Meanwhile, acetone poses genuine risks to the rubber seals, plastic fuel lines, elastomer components, and aluminum and metal alloys used throughout modern fuel systems, especially at concentrations above 1–2%. These risks can lead to fuel leaks, component failures, and repair bills of $500–$3,000 or more. For genuinely better gas mileage, focus on proven strategies: smooth driving, proper tire pressure, regular vehicle maintenance, weight reduction, and professional fuel system cleaning when deposits have accumulated.
Key takeaways:
| Takeaway | Detail |
|---|---|
| ❌ Acetone does NOT reliably improve gas mileage | No credible scientific evidence supports the claim |
| ❌ No EPA, ASTM, or manufacturer endorsement | Not approved as fuel additive by any authoritative body |
| ⚠️ Oak Ridge study widely cited by proponents | Not authenticated; likely fabricated or misattributed |
| ⚠️ Risk to rubber seals and plastic fuel lines | Damages seals, O-rings, and fuel lines at >1–2% concentration |
| ⚠️ Risk to aluminum and metal components | Accelerates corrosion in certain fuel system materials |
| ⚠️ Can void vehicle warranty | Unapproved additive use may void fuel system warranty |
| ⚠️ Unpredictable fuel formulation interactions | Can affect volatility, combustion, and stability |
| ✅ Fuel system cleaning effect is real | But same benefit from safer, purpose-built products |
| ✅ Better gas mileage approaches | Smooth driving, tire pressure, maintenance, reduce weight |
| ✅ Professional fuel system cleaners | 2–5% average improvement; proven safe and effective |
Remember:
Acetone + gas mileage = internet myth = not scientifically proven = do not use
No peer-reviewed study = no EPA approval = no ASTM listing = no automotive manufacturer endorsement
Oak Ridge National Lab study = not authenticated = likely fabricated = not a valid source
Acetone as fuel additive = one legitimate use: aviation fuel system icing inhibitor in avgas only
Acetone material risks: rubber seals, elastomers, plastic fuel lines, aluminum components
Concentration above 1–2% = real damage risk = fuel leaks = component failure
Repair cost from acetone damage: $500–$3,000+ depending on component
Fuel system cleaning benefit from acetone = real but available from safer products
Purpose-built fuel system cleaners: BG 44K, Chevron Techron, Lucas = proven safe and effective
Professional fuel system cleaning: 2–5% average gas mileage improvement
Driving habits: smooth acceleration/braking = 10–40% gas mileage improvement = biggest factor
Tire pressure: 3–5% per PSI below spec = free and easy maintenance
Engine tune-up: bad spark plugs = up to 40% fuel economy loss = regular maintenance
Does acetone improve gas mileage? No = use proven methods instead
Acetone added to gas = not recommended = not approved = not safe = not worth the risk
Does acetone improve gas mileage? No - there is no reliable evidence. Any perceived benefit comes from cleaning, not acetone itself. Acetone can damage fuel system components. Use purpose-built fuel system cleaners and proven driving and maintenance strategies instead.
Last updated: July 2026
Disclaimer: This guide provides general information about acetone as a fuel additive for educational purposes only. The claims about acetone improving gas mileage are not supported by credible scientific evidence. Adding acetone or any unapproved additive to your vehicle's fuel system may void warranties, damage fuel system components, and create safety hazards. Always follow your vehicle manufacturer's recommendations for fuel type, fuel additives, and maintenance. Never use unapproved fuel additives in your vehicle. The author and publisher assume no responsibility for any damage or harm resulting from the use of acetone or any other unapproved fuel additive.
